Arrangement of several ferrules for optical waveguides and process of manufacturing a belt of plastic ferrules

ABSTRACT

An arrangement of several ferrules for optical waveguides having at least one connection section, two ferrules respectively mutually connected by way of a connection section or mutually connected by way of a belt. In an advantageous embodiment, the ferrules are connected in one piece with the belt. In a process for producing a belt having plastic ferrules, the following process steps are implemented: Injection-molding a first plastic ferrule, conveying the finished plastic ferrule by a defined distance, and injection-molding a second plastic ferrule, so that it is connected with the first plastic ferrule. The process may further include belt segments which are injection-molded with the plastic ferrules.

BACKGROUND AND SUMMARY OF THE INVENTION

This application claims the priority of German Application No. 100 19392.7, filed in Germany on Apr. 19, 2000, the disclosure of which isexpressly incorporated by reference herein.

The invention relates to an arrangement of several ferrules for opticalwaveguides as well as to a process for producing a belt having plasticferrules.

In the case of all optical waveguides used for transmitting data, theproblem arises that the end of the fiber must be positioned veryprecisely. The radial as well as the axial position tolerances aredecisive for limiting the coupling losses. In almost all known technicalsolutions, a small tube-shaped part is pushed over the fiber end and isfastened there. This part is also called a ferrule, an insert or anoptical contact. In the case of optical waveguides made of glass as wellas those made of plastic, the problem arises of finding an efficientfastening method which meets the high technical demands. For thisreason, a very reliable mass production process is required which can beautomated. However, the ferrules often have to be introduced into theassembly process individually and in an oriented manner. When the supplytakes place as bulk material, a component-specific vibro-conveyer and acomponent-specific vibrating rail must therefore be mounted in front ofeach assembly station. Other comparable separating and feeding devicesare also known. The investment costs for these devices are considerable.

An object of the invention is to provide an arrangement for feeding theferrules to an assembling machine without the requirement ofhigh-expenditure separating and feeding devices.

This object is achieved by an arrangement of several ferrules foroptical waveguides with at least one connection section, at least twoferrules being connected with one another by way of the at least oneconnection section.

Furthermore, the object is achieved by an arrangement of severalferrules for optical waveguides, the ferrules being arranged on acontinuous belt and being fixed on the latter.

By connecting ferrules to form a belt, a simple solution is provided offeeding the ferrules to an assembling machine. Depending on theconstruction of the arrangement, only the position of the ferrules on orin the belt is defined, in which case, the ferrules can be held withplay, or a rotation of the ferrules is prevented.

When plastic material is used for the ferrules and the belt, a processis provided for producing a belt having plastic ferrules which includesthe following process steps:

-   -   injection-molding of a first plastic ferrule,    -   conveying the finished plastic ferrule by a defined distance,        and    -   injection-molding a second plastic ferrule, so that it is        connected with the first plastic ferrule.

The process is advantageous because the plastic ferrule as well as thebelt can be produced in the same manufacturing step. Since no additionalproduction step is required, the process according to the inventionsaves considerable costs.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of two plastic ferrules connected in one piece with abelt;

FIG. 2 is a view of two belt segments of the belt of FIG. 1;

FIG. 3 is a view of the molding-on geometry of a belt segment of FIG. 2;

FIG. 4 is a top view of the arrangement of FIG. 1;

FIG. 5 is a view of the arrangement of FIG. 1 with a plurality offerrules;

FIG. 6 is a cross-sectional view of the arrangement of FIG. 1; and

FIG. 7 is a view of another embodiment of an arrangement with ferrulesand a belt.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates two belt segments 4 of a belt 1 with ferrules 2molded thereto. The ferrules 2 are connected in one piece with beltsegments 1, but can be separated from the belt in a relatively simplemanner because cross-sectional reductions are provided at the connectionpoints between the ferrules 2 and the belt 1. The belt segments 4 have aU-shaped design. This design provides advantages in the manufacturingprocess. During an injection-molding operation, the ferrules 2 areinjection-molded around a mold core which, after the solidification ofthe plastic material, is pulled out again. A flat belt would impair thecore pull.

FIG. 2 illustrates the belt segments 4 without the ferrules 2. In thisrepresentation, it is shown that the connection sections 3 have asignificantly smaller cross-section than the adjacent sections. Theremoval is therefore very simple. However, since the belt 1 iscontinuous, the secure holding of the belt is ensured because of theU-shaped sections.

Molded-on sections 5 of the belt segments 4, which are provided for theinjection-molding-on of another belt segment 4, have a so-calledundercut geometry. When a new belt segment 4 is injection-molded to anexisting one, a cold injection-molding seam is created which representsa potential cracking point. The openings 6 in the molded-on section 5are penetrated when the plastic material is injection-molded-on, so thata “locking” takes place between the old belt segment and the newlyinjection-molded-on belt segment.

The molded-on section 5 in the embodiment of FIG. 2 is constructed inthree parts, in which case the center part is offset with respect to thetwo adjoining parts. This is easily visible again in FIG. 3. In thiscross-sectional view, in addition to the molded-on section 5, plasticinjection molding material 7 of the newly injection-molded-on beltsegment is also visible.

The injection molding material 7 of the new belt segment extends throughthe openings of the molded-on section 5. The openings are each conical,so that a secure hold is provided between the molded-on section 5 andthe new belt segment, and the two parts cannot detach from one anothereither in the upward or in the downward direction. The secure and stableconnection between the two belt segments 4 is important because beltsare normally wound onto reels. This indicates that the belt is stressedwith respect to bending and thus is subjected to a special strain.

The position of the ferrules 2 in the belt segments 4 is againillustrated in FIG. 4. The connection of the ferrules 2 with the beltsegments 4 is situated on the connection sections 3. A connector-sideend 8 of the ferrules 2 therefore remains free of a burr, so that afinishing is not required.

FIG. 5 illustrates how a plurality of belt segments 4 with ferrules 2forms a belt 1. During the feeding into a machine, the belt 1 is movedin the direction of the arrow 9. The ferrule has already been removedfrom the first belt segment. The removal of the ferrules from the belt 1can take place by the assembling machine. In this case, the holdingtools for the holding during the fabrication with an optical waveguidecan simultaneously be used as a tool for detaching the ferrules from thebelt.

FIG. 6 is a longitudinal sectional view of the belt with ferrules 2still disposed therein. The thin connection webs of the connectionsections 3 are easily visible. It is also clearly illustrated how thetwo shown belt segments blend into one another.

In a simplified embodiment, the ferrules can be in a direct connectionwith one another. The ferrules are then no longer connected in one piecewith the belt, but have a connection section which connects the ferruleswith one another. The problem of this simplified arrangement is thestability of the entire belt. Furthermore, it is conceivable that theferrules are not connected with the belt in one piece but are arrangedon the latter by clamps. The clamping can take place without play orsuch that the ferrules can, for example, still rotate. The clamping canbe implemented according to FIG. 7, where the belt includes a lower belt10 and an upper belt 11. The ferrules 2 are received and held betweenthe two belts 10 and 11. The removal from the belt in this case takesplace by the spreading of the two belts or by the pushing-out of onebelt side.

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

1. Arrangement of several ferrules for optical waveguides with aplurality of connection sections, wherein at least two ferrules areconnected with one another by at least one of a plurality of connectionsections, at least one of the plurality of ferrules and at least one ofthe plurality of connection sections are formed in one piece, and theconnection sections form a belt on which the ferrules are detachablyfixed, such that when the ferrules are detected, the connection sectionsremain together in belt form.
 2. Arrangement according to claim 1,wherein the connection sections are flexible.
 3. Arrangement accordingto claim 1, wherein the connection sections have a section fixing theferrules to the belt of a reduced cross-section.
 4. Arrangementaccording to claim 1, wherein the belt is a plastic injection-moldedpart.
 5. Arrangement according to claim 4, wherein a belt segment forthe injection-molding-on of another belt segment has a geometry by whichthe two belt segments are locked.
 6. Arrangement according to claim 1,wherein the plastic ferrules are connected in one piece with the belt.7. Arrangement according to claim 6, wherein the ferrules and the beltare connected with one another at an end area of the ferrule. 8.Arrangement according to claim 1, wherein the belt is formed by mutuallyconnected U-shaped bridge segments.
 9. Arrangement according to claim 1,wherein the belt includes an upper and a lower belt between which theplastic ferrules are received.
 10. Arrangement according to claim 1,wherein the plastic ferrules are fixed on the belt such that theferrules can be rotated about a longitudinal axis.
 11. A method ofcoupling an optical waveguide, comprising: providing an arrangement offerrules, locating a ferrule of the arrangement over an end of theoptical waveguide, separating the ferrule from the arrangement offerrules, and fastening the ferrule to the optical waveguide, whereinthe arrangement of ferrules has a plurality of connection sections, atleast two ferrules are connected with one another by at least one of aplurality of connection sections, at least one of the plurality offerrules and at least one of the plurality of connection sections areformed in one piece, and the connection sections form a belt on whichthe ferrules are detachably fixed, such that when the ferrules aredetected, the connection sections remain together in belt form.
 12. Amethod according to claim 11, wherein the connection sections areflexible.
 13. A method according to claim 11, wherein the belt is formedby mutually connected U-shaped bridge segments.
 14. A method of makingferrules for optical waveguides, comprising: providing at least twoferrules with a plurality of connection sections, and connecting the atleast two ferrules with one another by at least one of a plurality ofconnection sections, wherein at least one of the plurality of ferrulesand at least one of the plurality of connection sections are formed inone piece, and the connection sections form a belt on which the ferrulesare detachably fixed, such that when the ferrules are detected, theconnection sections remain together in belt form.
 15. A method accordingto claim 14, wherein the connection sections are flexible.